Electromagnetic reversing valve



2,693,930 ELECTRoMAGNETIc REvERSlNG VALVE Carnia M. Carter, Nashville,Tenn., assignor of fifty-oney per cent to M. T. Gossett, Nashville,Tenn. Application July zo, 1949, seriaiNo. 105,783 Y z Claims. (c1.251-44) The present invention relates to new and useful improvements 1nreversing valves and more particularly to `an electromagnetic reversingvalve to reverse or change direction of ow of refrigerant gases within arefrigerating system.

An important object of the valve is to provide a positive, convenientand simple control to the act of reversing the refrigerant cycle in anyreverse cycle refrigerating system.

Another object is to provide a device of this character of simple andpractical construction, which is efficient and reliable in operation,relatively inexpensive to manufacture and otherwise well adapted for thepurposes for which the same is intended.

Other objects and advantages reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming part hereof, wherein likenumerals refer to like parts throughout, and in which:

Figure 1 is a side elevational view of the valve;

Figure 2 is a vertical sectional view showing the reversing plunger inraised position;

Figure 3 is a similar view showing the plunger in a lowered position;

Figure 4 is a transverse sectional view on a reduced scale taken on aline 4-4 of Figure 2, and

Fi3gure 5 is a similar view taken on aline 5-5 of Figure Referring nowto the drawings in detail wherein for the purpose of illustration I havedisclosed a preferred embodiment of the invention, a valve body isdesignated at 1 and is constructed of suitable material and machinedinside to receive a steel sleeve 2 pressed in and made gas tight. Thesleeve is machined to provide upper and lower cylinders 3 and 4, theupper cylinder being of increased diameter to receive an enlarged upperpiston forming head 5 of a plunger 6 forming a lower piston which worksin lower cylinder 4.

Exterior of plunger 6 and interior of cylinder 4 are finished topolished surfaces with very small clearance so that when covered with alight lm of oil, as in a refrigerating system, very little or no gas canpass from one point to another along the walls of the cylinder. Head 5and cylinder 3 do not have quite so close a clearance, as the operationof the valve depends on a very small amount of gas passing from bottomto top of plunger head 5 in cylinder 3. The head 5 may be spaced fromthe top of the cylinder 3, when said plunger 6 is fully raised, by asmall teat 5 on said head.

The lower portion of body 1 is provided with ports 7, 8, 9 and 10 at 90with respect to each other and connected to lower cylinder 4 by alignedports 7a, 8a, 9a and 10a in sleeve 2.

Plunger 6 is formed with upper and lower pairs of circumferential slots11 and 12.

A passage 13 is drilled through sleeve 2 and body 1 at an angle,commencing at bottom of upper cylinder 3 and ending in port 9. Behindsteel sleeve 2 and in line with port 7 are upper and lower grooves 14and 15 cut in body 1 from top to bottom of the body. At the top, thegroove 14 is notched as at 16 to coincide with port 17 drilled in valvehead 18 secured on top of body 1. The port 17 leads to the bottom of acentral chamber 19 in head 18 and in the lower portion of which a plug21 is threaded having a vertical orifice 20 with a valve seat 20a at itsupper end.

To one side of plug 21 a small passage 22 is drilled "ice '- throughhead 18 to its bottom and extending to the-top of cylinder 3 above.plungerhead 5.

The head 1s is brass and is driued and tapped to' receive a magnetplunger housing assembly 23 having v a neck 24 threaded to the top ofhead 18.

An electromagnetically operated valveV 32 is mounted in assembly -23 andincludes a magnet plunger 25, stationary magnet 26, magnet coil 27, coil`cover 28, cover stud 29, cover nut 30, needle '31 extending upwardlyfrom lvalve 32 and all of which follow the well known L. electromagnetprinciple andare of conventional construction and arranged to open andclose the valve 32 with valve seat 20a. The electromagnetically operatedvalve is used in connection with this invention only as a means ofoperating pilot lines through the ports.

A square key 33 of sufficient length to guide the plunger 6 through fulllength of its travel is pressed into a groove 34 in lower end of steelsleeve 2 in direct line with suction port 7. Key 33 slides in a keyway35 cut into plunger 6 and extending from the bottom of the plunger intoline port 7a in sleeve 2 which coincides with suction connection 7 whenplunger is at top posit1on.

Between body 1 and head 5 is a head gasket 36 and between body 1 and abase plate 37 is a base plate gasket 38.

In the operation of the device, the discharge or high pressure line of areverse cycle refrigeration or air conditioning system is connected toport 9 and the suction or low pressure line is connected to port 7.Ports 8 and 10 are also connected in the system to accomplish a reversellow of fluid and are alternately connected to ports 7 and 9, asindicated in Figures 4 and 5, during the reversing action of the valve.

The area 39 above head 5 of plunger 6 is equal to the combined area 40under the shoulder of head 5 plus area 41 under the bottom plunger 6.Since area 40 is always subjected to high pressure from port 9 enteringpassage 13, and area 41 is always subjected to low pressure from port 7and passage 15, the combined moving force of these two pressure areas isalways acting to raise plunger 6 to its top position. A small teat 41may be provided on the bottom of plunger 6 to space said area 41 fromthe gasket 38 when the plunger 6 is' fully lowered, and for a purposewhich will be clear.

When orice 20 is closed by valve 32 and high pressure allowed to buildup in area 39, due to the loose lit of head 5 in cylinder 3, the actingforce of high pressure on area 39 overcomes the combined acting force ofhigh pressure on area 40 and low pressure on area 41 and plunger 6 isaccordingly pushed downwardly to the position shown in Figure 3. Slot 11then connects port 9 with port 10 and port 8 with port 7, as shown inFigure 5, to reverse the ow.

When valve 32 is raised to open orifice 20 and allowing pressure on area39 to become equal to pressure on area 41, then acting force of highpressure on area 40 plus low pressure on area 41 overcome the actingforce of low pressure on area 39 and plunger 6 is raised and held in itsuppermost position. Slot 12 then connects port 7 with port 10 and port 8with port 9.

Having described the invention, what is claimed as new 1s:

1. In a uid flow reversing valve, a valve body including a lowercylinder having a closed lower end, and an upper relatively largercylinder, a lower piston of the same diameter and substantially the samelength as said lower cylinder working in said lower cylinder and havingan enlarged piston on its upper end working in said upper cylinder,first and second pairs of diametrically opposite ports in said lowercylinder arranged in pairs in angular relation, the ports of the irstpair communicating with said lower and upper cylinders respectivelybelow said pistons and being adapted to admit liuid under low and highpressure to said cylinders respectively, said lower piston having abottom low pressure area constantly exposed in said lower cylinder tolow pressure and tending in response to low pressure against the same toraise said pistons, said upper piston having a bottom high pressure areatending in response to high pressure against the same to raise saidpistons ageaaaao,

to permit uid underhiglrk pressure. to bieeclupwardly past said upperpistontto-accumulate above the same and act against said top areaf to.lower said pistons, meanson saidy lower pistoni alternately.- connectingthe ports of the irst pair with the'ports offthefsecond:pair` when saidpistons-.are raised and loweredirespectively,

the ports of` saidipairsfbeingadapted when alternatelyA connectedbyfsaid means ,to establish reverse. iiow1 paths forvpassng liquidthrough said lower cylinder,- and valve controlled passage means. insaid bodyv for vequalizinge pressure, accumulated above. said upperpistom Witlil'.l

that:.below` said lower: piston to permit' raising =o2said 4f, pistonsin response to high and low pressures' acting against-said" bottomr`higlr and low'pressure'- areas'.l

2. A valve according to claim 1, said passage means comprising apressure equalizing passage in said body extending from the closed endof said lower cylinder to the top of the upper cylinder.

References. Cited in the ile of this patent UNITED STATES PATENTS NumberName Date 685,930' Nethery Nov. 5, 1901 2,329,001 Robinson .Sept. 7,1943 2,379,181 Pontius June 26, 1945 2,489,450 Crookston Nov. 29, 19492,550,723 Ross May 1, 1951

